Weighing-scale



(No Model.) 2 Sheets-Sheet 1.

F. S. WASHBURN.

WEIGHING SCALE.

No. 375,520. Patented Dec. 27, 1887.

(No ModeL) 2Sheets-Sheet 2.

Y I. s. WASHBURN.

WBIGHING SCALE.

No. 375,520. Patented Dec. 27, 1887.

I IlIlllllllllllllllll/lfill UNITED STATES;

PATENT OFFICE.

FRANK s. WASHBURN, or CHICAGO, ILLINOIS.

WEIGHING-SCALE.

SPECIFICATION forming part of Letters Patent No. 375,520, dated December27, 1887.

Application filed June 4, 1887.

T all'whom it may concern:

Be it known that I, FRANK S. WAsHBURN, residing at Chicago, in thecounty of Cook and State of Illinois, and a citizen of the UnitedStates, have invented certain new and useful.

Improvements in \Veighing-Scales, of which the following is aspecification, reference being bad to the accompanying drawings,in whichFigure 1 is aside elevation of a scale-beam with my improvementsattached; Fig, 2, a side elevation of the outer end of the long arm ofthe scale-beam; Fig. 3, an end view of the same part; Fig. 4., alongitudinal vertical section of the devices added for preventingvibrations and for registering weights; Fig. 5, an end view with theshort arm of the scale- 1 beam in section, showing the manner of formingand connecting the yoke to the scale-beam; Fig. 6, a plan view of theliquid-cylinder.

4 The object of this invention is to attach a .device to aplatform-scale, so that moving cars or vehicles can be weighed while inmotion or without stopping them; and its nature consists in theimprovements hereinafter described and claimed as new.

In the drawings, Aindicates the beam-frame of an ordinaryplatform-scale; B, the scalebeam; 0, the poise; D, the hanger; E, rodconnecting the beam with the platform-levers; F, regulator; G,counter-balance; II, liquidcylinder; H, diaphragm-ring with bridge; I,

supports for the cylinder; J, vibration-regulator; K, hangers; L,hand-wheel and shaft for operating the regulator J; M, overflow- 5receptacle; a, eccentric or scroll groove in the regulator J; 1), pin onscale beam passing into or through the groove a; a, yoke or saddle; d,knife-edge on the upper plate of the 1 yoke; d, point on the upper endof the rod f; 0 e, set-screw for locking the rod f to the yoke;

. f, rod connecting the scale-beam with the liquid-cylinder; g,turn-buckle or sleeve-nut; h, adj usting-collars with set-screws; i,diaphragmplate; j, diaphragm; k, liquid-reservoir; Z,

5 bent tube; m,stop-cocks; n,scale-plate, and 0 glass tube.

. The parts indicated by the letters A, B, O,

l D, E, F, and G are or may be of the usual construction, and the rod Econnects the scalesolbeam with the usual system of levers, upon whichthe platform is supported in the ordi- Serial No. 240,311. (No model.)

nary manner. The outer or long arm of the lever scale-beam is providedwith a pin, 1),

- near its end,w hich engages with the curved or scroll slot in theregulator J, which pin is directly beneath the shaft L, so that thevibrations of the pin do not cause a tendency to turn or rotate theregulator J. As shown in Fig. 1, the end of the beam is at its highestpoint, while the rotation of the scroll-disk to the limit of the slotplaces it in its lowest position. The slot must be large enough to givethe pin a sufficient play to permit of accurate weighing, and the pin bmay be a single projecting pin,or it maybe provided with an antifrictionroller, if desired. This arrangement is important, as it permits of thescale-beam being adjusted to give the diaphragm of the liquidcylinder aproper position, and prevents vibrations of a sufficient length or rangeto communicatedisturbing vibrations to the liquid, which might otherwisebe caused by the sudden increase or decrease of the load and by therunning on and off of moving cars or vehicles.

The short arm of the lever scale-beam is' provided in the form shownwith a slight extension to adapt it to receive the yoke c, which is thebest mode of connecting the beam with the diaphragm of theliquid-cylinder known to me. This end of the short arm of the beam isformed as shown in cross-section at Fig. 5- that is, with a conical holeon the under side, into which the point (1 enters. The yoke c ispreferably made in the form shown in said Fig. 5-that is, with twocrossplates and connecting-rods. The upper cross-plate is provided witha knife-edged projection, d, which rests upon the scale-beam, and thelower plate is provided with a set-screw, e, by which the rod f can belowered, so as to attach it, and then raised into position to insert thepoint d in the corresponding hole in the beam B. This construction ofthe yoke 0 gives it the proper movement, and at the same time retains itin position on the beam.

The connecting-rod f is preferably made in two parts connected by theturn-buckle or sleeve 9, the screw-threads being right and left, so thatthe length of the rod may be vavaried and adjusted. The rod is alsoprovided with adjustable collars h on opposite sides of ICO the bridgeorcross-bar H, which will prevent the undue straining of the diaphragmby reason of any accident or sudden movement, because when the roddescends a certain distance the collar will strike a bridge orobstruction, which will stop the farther descent of the rod, so that itis impossible to punch the diaphragm down into the fluid-cup.

The hole through the bridge is large enough to avoid friction, as theslightest amount of friction prevents accurate weighing.

The diaphragm is formed of a central plate, i, preferably made in twoparts for the purpose of more easily and firmly attaching it to thediaphragm j. The rod f is attached to these center plates or pistons, asshown in Fig. 4. The size of these plates 2' determines the effectivearea of pressure which affects the rod f. The diaphragm j is made offlexible material, which should be made or rendered impervious to theliquid contained in the cylinder H, and it is attached to this cylinderas shown in Figs. 4 and 6, or by other suitable means, the area ofpressure at the top of the cylinder being very considerably larger thanthe diameter of the tube leading to the scale n, so that any slightmovement of the diaphragm shows a considerable variation on theliquidscale.

The diaphragm is preferably a fabric commonly known as London pocketing,underlined with a thin sheet of rubber; but leather, laminated rubber,or other suitable material may be used.

The cylinder H has an interior diameter of from two to six inches, fourand a half being preferable. Abent tube, Z, is connected with thecylinder at one side, and may be provided with a stop cock, m, and alsowith an enlargement, as shown at Fig. 4, which enlargement will preventair being drawn into the cylinder H in case of any excessive upwardmovement of the diaphragm in adjusting or by accident; but suchenlargement is not absolutely essential to the proper operation of thedevice,and the pipe Z may therefore be of the same size for its entirelength between the tube 0 and cylinder H.

The glass tube '0 is made of sufficient length to show the extremevariations of the liquid column in the tube, and it is attached to thepipe land to the overflow-bulb M by suitable couplings, which willprevent the escape of any liquid. The cylinder H,as shown in Fig. 4, isprovided with a reservoir, R, from which the liquid used is permitted toflow into the cylinder in filling it, and afterward, as occasion mayrequire, by simply turning the stopcock, which is turned back when thefilling is completed. The filling of the cylinder H with liquid shouldbe performed in such manner as to entirely exclude or permit the escapeof air, which may be accomplished by tipping it, as the presence of airor other compressible gas between the diaphragm and the liquid willdetract from its usefulness and accuracy.

The liquid contained in the cylinder should be non-freezing for exposedsituations, and as mercury and the oils oxidize I do not regard them assuitable liquids to be used. Where the scale-beam is housed water may beused; but where it is not, wood alcohol is the best liquid known to mefor filling the cylinder. When either water or wood alcohol is used itwill improve the facility of reading the scale to color the liquid.

It will be understood that the rod f receives the same benefit fromcompounding the levers beneath the platform that the rod E does, so thatthe pressure upon the cylinder H is correspondingly light ascomparedwith the weight on the platform.

In weighing atrain of cars the poise G is set to indicate a weight lessthan that of any car in the train; or, in a train where the cars varygreatly in weight, it may be set several times, but always showing lessthan the weight of the next car to be weighed. As a car rollsontotheplatform,thesuddenly-appliedweights of the successive pairs ofwheels and the sudden relief from the car just passing off gives thebeam B a series of severe shocks or blows through the levers connectingit with the platform.

Any movement of the scale-beam is communicated to the rod f eitherthrough the point (1 orknife-edge (1 bearing upon the short arm of thebeam B. Any movement, tremor, or vibration of the scale-beam is,'throughthe nature of the connection, conveyed to the diaphragm-plates i, and bythem to the diaphragm j, where it is checked, as,the diaphragm beingpractically inelastic and in direct contact with the incompressibleliquid in thecylinder,such sudden movement or vibration,which is in thenature of a shock or blow, is absorbed or connteracted by the inertia ofthe incompressible liquid in the cylinder, for the reason that theliquid can only escape through the small orifice leading to the tube Z,and the friction of the liquid on the walls of the tube. Any upward blowon the rod f is effectually checked, because the diaphragm, beingdirectly connected to it,must rise with it,which movement cannot takeplace without an extraordinarily rapid flow of liquid from the tube Zback into the cylinder, or without lifting the diaphragm against thepressure of the atmosphere. The vibrations are all through a very smallor limited space, so that the necessity of practically inelastic meansof controlling them is necessary. While these dynamic effects are beingresisted, the static load, over and above what is indicated by the poiseO, is being brought into equilibrium with the pressure on the diaphragm,and shown by the height of the column in the tube 0 in connection withthe scale at.

The reduction of the column in the tube 0 to a steady height shows thecomplete absorption of all vibrations, and the figures on theindicating-plate 11. represent the weight which is to be added to theweight shown by the poise 0, thus giving the total weight of the load onthe platform. These fluctuations in' the tube come to a rest so speedilythat the excess of weight above that indicated by the poise can bedetermined within a sufficiently 5 short space of time to accuratelyweigh mov- 10 rangement is deemed preferable, it is evident that theymay be attached to the long arm near the hangerD without any materialchange in structure or operation.

WhatI claim as new, and'desire to secure by 1 Letters Patent, is.-

1. The combination,with a lever scale-beam and poise, of a liquidindicator arranged to operate with the fulcrum end of thebeam,snbstantially'as and for the purposes specified.

2o 2. The combination of the cylinder H, diaphragm z j, adjustable rodf, and yoke c with a lever scale-beam, substantially as described.

3. The combination of the yielding diaphragm ij and rod f with thebridge H and limit collars or stops h, substantially as described.

4. The combination of the beam B, rod f, and cylinder H, having ayielding top or diaphragm, with the tubes Z 0 and overflow-bulb M,substantially as described. N

5. The combination of a. lever scale-beam having afluid indicator orscale connected with its short arm with the disk J, having a scrollslot,at, and pin b on the long arm of the beam, whereby undue pressure on thefluid-holder is prevent-ed, substantially as specified.

FRANK S. WASHBURN.

WVitnesses:

ALBERT H. ADAMS, HARRY T. J ONES.

